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Watts Relief Valve: FNPTF x FNPTF, 3/4 in x 3/4 in, Copper Silicon Alloy - ASME Section XIII Hot Water Pressure Relief Valves
WattsASME Section XIII Hot Water Pressure Relief Valves

Watts Relief Valve: FNPTF x FNPTF, 3/4 in x 3/4 in, Copper Silicon Alloy

The WATTS 3/4 LF174A 75 FS is an ASME Section XIII hot water pressure relief valve with 3/4 in x 3/4 in FNPTF connections, made of copper silicon alloy, and rated for a maximum operating pressure of 150 psi (MPN 3/4…

SKU 3G-OTH-442462

Also listed as: 34LF174A75FS · 3 4 LF174A 75 FS · 3-4-LF174A-75-FS

Brand
Watts
Item
Relief Valve: FNPTF x FNPTF, 3/4 in x 3/4 in, Copper Silicon Alloy
Category
ASME Section XIII Hot Water Pressure Relief Valves
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Local availability & support — Singapore

Local office
20 Woodlands Link #09-05, Singapore 738733
Phone
+65 8878 8355
Delivery
Same-day or next-business-day delivery within Singapore for in-stock items; 7–14 days for factory-order parts from Europe.
Payment
Invoicing in SGD. PayNow, bank transfer, and corporate PO accepted.
Ships to
Singapore

Technical Specifications

Watts
Manufacturer Part Number
3/4 LF174A 75 FS
Type
3/4 in x 3/4 in, Copper Silicon Alloy
Max. Op Pressure
150 psi

Technical Documents

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Watts Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The WATTS 3/4 LF174A 75 FS is an ASME Section XIII hot water pressure relief valve with 3/4 in x 3/4 in FNPTF connections, made of copper silicon alloy, and rated for a maximum operating pressure of 150 psi (MPN 3/4 LF174A 75 FS).

Frequently Asked Questions

What is the Watts LF174A relief valve used for?

The Watts LF174A is an ASME Section XIII hot water pressure relief valve used in commercial and residential hydronic heating systems. It protects boilers and water heaters from overpressure by automatically discharging water when system pressure exceeds 150 psi, preventing equipment damage and ensuring safe operation.

What are the specifications of the Watts 3/4 LF174A 75 FS relief valve?

The Watts 3/4 LF174A 75 FS is a copper silicon alloy relief valve with 3/4 inch FNPTF female threaded connections on both inlet and outlet. It has a maximum operating pressure of 150 psi and is ASME Section XIII certified for hot water service. The manufacturer part number is 3/4 LF174A 75 FS.

Where to buy Watts relief valves worldwide?

3G Electric supplies Watts relief valves worldwide. As a global industrial equipment distributor since 1990, we handle full logistics, customs clearance, and delivery to your site. Contact our team for pricing and lead time on the Watts LF174A or other ASME relief valves for your region.

How to install a Watts LF174A pressure relief valve?

Install the Watts LF174A in the hot water outlet line of the boiler or water heater, with the valve stem oriented vertically or within 45 degrees of vertical. Use pipe thread sealant on the FNPTF connections, ensure no shutoff valve is placed between the system and the relief valve, and route the discharge pipe to a safe drain location per local codes.

Used in

Common applications for Watts
Industrial burner gas safety systems — Watts HF2000 filters with GF-series seal kits maintain clean, regulated gas supply to burner pilot and main flame controls
Commercial heating and boiler installations — Modular filter assemblies support preventive maintenance and component replacement without full system shutdown
Process gas delivery pipelines — DN25 through DN125 filter bodies accommodate varying flow rates and inlet pressures across manufacturing and chemical processes
Gas pressure regulation benches — Multi-stage Watts filter platforms integrate with pressure reducers and safety shutoff valves in test and calibration environments
Equipment retrofit and upgrade projects — Available connection sizes and seal kits enable adaptation of newer Watts components into legacy gas control systems
Planned maintenance and spare-parts inventory — Filter seal kits allow facilities to stock consumables in advance, reducing downtime during scheduled gas system servicing

Watts Products

3G Electric supplies Watts asme section xiii hot water pressure relief valves. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

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Compatible alternatives & equivalents

Cross-referenced by specification & description
WATTS Relief Valve: FNPTF x FNPTF, 3/4 in x 3/4 in, Copper Silicon Alloy, 150 psi Max. Op Pressure (MPN 3/4 LF174A 100 FS)
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WATTS Relief Valve: FNPTF x FNPTF, 3/4 in x 3/4 in, Copper Silicon Alloy, 150 psi Max. Op Pressure (MPN 3/4 LF174A 100 FS)
WATTS Relief Valve: FNPTF x FNPTF, 3/4 in x 3/4 in, Copper Silicon Alloy, 150 psi Max. Op Pressure (MPN 3/4 LF174A 150 FS)
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WATTS Relief Valve: FNPTF x FNPTF, 3/4 in x 3/4 in, Copper Silicon Alloy, 150 psi Max. Op Pressure (MPN 3/4 LF174A 150 FS)
WATTS Relief Valve: FNPTF x FNPTF, 3/4 in x 3/4 in, Copper Silicon Alloy, 150 psi Max. Op Pressure (MPN 3/4 LF174A 125 FS)
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WATTS Relief Valve: FNPTF x FNPTF, 3/4 in x 3/4 in, Copper Silicon Alloy, 150 psi Max. Op Pressure (MPN 3/4 LF174A 125 FS)
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WATTS Relief Valve: FNPTF x FNPTF, 2 in x 2 in, Bronze, 150 psi Max. Op Pressure (MPN 2 174A 100 FS)
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WATTS Relief Valve: FNPTF x FNPTF, 1 in x 1 in, Copper Silicon Alloy, 150 psi Max. Op Pressure (MPN 1 LF174A 150 FS)
WATTS Relief Valve: FNPTF x FNPTF, 2 in x 2 in, Bronze, 150 psi Max. Op Pressure (MPN 2 174A 150 FS)
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WATTS Relief Valve: FNPTF x FNPTF, 2 in x 2 in, Bronze, 150 psi Max. Op Pressure (MPN 2 174A 150 FS)

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